JP2023136826A - Stereo molding method, and manufacturing method of stereo molded object - Google Patents

Abstract

To provide a stereo molding method capable of removing a molded object from a molding table without spilling a core material from a core part, in a stereo molding method of a so-called core shell method.SOLUTION: A stereo molding method for molding a stereo molding 1 containing a core material 5 comprises: a shell molding step (S1) in which a shell 2, which is an outer shell layer of a stereo molding 1, is molded on a molding table 15 using a shell material 3; a core material filling step (S2) for filling the core material 5 in a core part 4 that is a part surrounded by the shell 2; a shell removing step (S5) for removing the shell 2 from the modeling table 15; and a leakage prevention part forming step (S4) for providing a leakage prevention part 7 to an opening 2a of the shell 2 between the core material filling step (S2) and the shell removing step (S5).SELECTED DRAWING: Figure 2

Description

The present invention relates to a three-dimensional modeling method and a method for manufacturing a three-dimensional object, and more particularly, to a three-dimensional modeling method for forming a three-dimensional object using an additive manufacturing technique such as 3D printing, and a method for manufacturing a three-dimensional object.

The term 3D printer is widely used as a name for manufacturing equipment that uses 3D printing technology. A 3D printer uses a computer to calculate the cross-sectional shape of a model based on three-dimensional CAD data, divides the model into thin slice-shaped cross-sectional components, and forms the cross-sectional components using various methods. This is a three-dimensional modeling device that creates a desired object by layering these layers. 3D printing technology is often used internationally as a synonym for Additive Manufacturing Technology, and the Japanese translation is additive manufacturing technology.

ASTM International, an international standards organization, broadly categorizes additive manufacturing methods into the following seven types.
(1) Liquid bath polymerization method (Vat Photopolymerization)
(2) Material extrusion method
(3) Powder bed fusion method
(4) Binder Jetting
(5) Sheet lamination method
(6) Material Jetting
(7) Directed Energy Deposition

(1) The liquid bath polymerization method was put into practical use the earliest of these, and was used for rapid prototyping under names such as stereolithography and SLA (Stereolithography) even before the name 3D printer became common. It was used for a purpose.

(2) Material extrusion is also called fused deposition modeling or FDM (Fused Deposition Modeling), and in many cases, a modeling material made of thermoplastic resin is heated to melt it into a fluid state, and then it is extruded through a nozzle while being laminated. This is a method of modeling.

(3) Powder bed fusion bonding method and (4) binder injection method are characterized in that they use powder or granular material as the modeling material.
(3) The powder bed fusion bonding method is also called powder sintering, SLS (Selective Laser Sintering), SLM (Selective Laser Melting), etc.

(4) The binder jetting method is also called inkjet type binder jetting or CJP (Color Jet Printing), and like the (3) powder bed fusion bonding method, it uses a material bed made of modeling material powder, but the material In this method, a binding material that has the function of an adhesive that binds the modeling material powder to the floor is selectively ejected from an inkjet head or the like to bind the modeling material powder to each other and create a model.

(5) As the name suggests, the sheet lamination method is a method in which a three-dimensional object is created by cutting sheet materials such as paper or plastic films into laminated cross-sectional shapes, and sequentially laminating and gluing them.

(6) The material jetting method is also called inkjet material jetting or MJP (Multijet Printing), and the viscosity of the modeling material is often slightly lower than that of the (2) material extrusion method, so it is similar to the ink of an inkjet printer. Instead, this is a method in which modeling material is discharged and layered in layers.
Many 3D printers that have been commercially available for personal use in recent years employ (2) a material extrusion method or (6) a material injection method.

(7) The directional energy deposition method is also called laser deposition, LMD (Laser Metal Deposition), etc. The directional energy deposition method is a method in which modeling materials are stacked while supplying the modeling materials and selectively applying energy at the same time.
[Problem to be solved by the invention]

As one of the technologies related to the above-mentioned additive manufacturing technology, the present applicant has proposed in Patent Document 1 below, in which the outer layer (shell) of a three-dimensional structure is first formed using a shell material, and then the core layer is formed using a shell material. We are proposing a three-dimensional modeling method that uses material to model the interior (core part) of a previously modeled outer shell layer. In this specification, this method is also referred to as a core-shell method.

FIG. 8 is a perspective view schematically showing an example of a three-dimensional structure formed by the core-shell method. The three-dimensional structure 100 has a shell 2 serving as an outer shell layer, and a core material 5 is filled in a core portion 4 surrounded by the shell 2 and hardened.

For example, in a method of manufacturing a core-shell type three-dimensional object as shown in FIG. 8 using a three-dimensional modeling apparatus using the liquid bath polymerization method described above, a modeling table disposed in a liquid tank for shell material is used. A shell 2, which is an outer shell layer, is formed on the top, and a core portion 4 surrounded by the shell 2 is filled with a liquid core material 5. Thereafter, the molding table is raised above the liquid tank surface, and the operator removes the shell 2 formed on the molding table from the molding table. Then, the removed shell 2 is heated in a heating furnace or the like to harden the liquid core material 5 in the core portion 4, thereby completing the modeling of the three-dimensional object 100.

FIG. 9 is a partial sectional view schematically showing a state in which a shell modeled using a core-shell method on a modeling table using a three-dimensional modeling apparatus using a liquid bath polymerization method is brought out onto the liquid tank surface of the shell material.
Moreover, FIG. 10 is a partial sectional view schematically showing a scene in which a shell modeled by the core-shell method is removed from a model table.

In the state shown in FIG. 9, a shell 2, which is an outer shell layer, is modeled on a modeling table 15, and a core portion 4 surrounded by the shell 2 is filled with a liquid core material 5. Further, between the modeling table 15 and the shell 2, a support portion 6 is formed using the shell material 3 in order to support the shell 2.

As shown in FIG. 10, when removing the shell 2 from the molding table 15, the operator gradually inserts a peeling tool 50 such as a spatula or scraper between the shell 2 and the molding table 15, and supports it. The shell 2 is removed from the modeling table 15 while breaking the part 6.
At this time, since the core material 5 filled in the core part 4 is in a liquid state, when removing the shell 2 from the modeling table 15 with the peeling tool 50, if the shell 2 is tilted or vibration is applied to the shell 2, the As shown in FIG. 10, there was a problem in that the core material 5 spilled from the core portion 4.

JP 2019-136923 Publication

Means to solve problems and their effects

The present invention has been made in view of the above-mentioned problems, and provides a three-dimensional modeling method in which a shell can be removed from a modeling table without spilling core material from a core part in a so-called core-shell three-dimensional modeling method, and a three-dimensional modeling method for three-dimensional modeling. The purpose is to provide a manufacturing method.

In order to achieve the above object, the three-dimensional modeling method (1) according to the present invention includes a shell modeling step of modeling a shell, which is an outer shell layer of a three-dimensional model, on a support member using a shell material;
a core material filling step of filling a core portion, which is a portion surrounded by the shell, with a core material, which is a liquid phase material;
a shell removal step of removing the shell from the support member;
A three-dimensional modeling method for forming a three-dimensional object including the core material,
The present invention is characterized in that a leak prevention part forming step is provided between the core material filling step and the shell removal step, in which a leak prevention portion is provided at the opening of the shell.

According to the three-dimensional modeling method (1), the leakage prevention portion forming step is provided between the core material filling step and the shell removal step, so that the leakage prevention portion is formed at the opening of the shell. It becomes possible to perform the shell removal step in the provided state. By providing the leakage prevention part at the opening of the shell, even if the shell is tilted or vibration is applied to the shell during the shell removal process, the core material will not be removed from the core part. There is no risk of spillage, and the shell can be removed from the support member without spilling the core material from the core portion.

In addition, the three-dimensional modeling method (2) according to the present invention includes, in the three-dimensional modeling method (1),
The leakage prevention part is characterized in that it is shaped by curing at least a portion of the shell material located on the core material.

According to the three-dimensional modeling method (2), the leakage prevention part is modeled by curing at least a part of the shell material located on the core material, so that after the core material filling step is completed, , the leakage prevention part can be easily and efficiently shaped.

In addition, the three-dimensional modeling method (3) according to the present invention includes, in the three-dimensional modeling method (2),
The hardening depth of the shell material when forming the leakage prevention part is deeper than the hardening depth of the shell material when forming the shell.

According to the three-dimensional modeling method (3), the hardening depth of the shell material at the time of modeling the leakage prevention part is deeper than the hardening depth of the shell material at the time of modeling the shell, so the leakage prevention part is thicker. parts can be efficiently modeled in a short time.

Further, in a three-dimensional modeling method (4) according to the present invention, in any of the three-dimensional modeling methods (1) to (3), the shell is formed in a shell material tank into which the shell material is injected,
In the leakage prevention part forming step, the leakage prevention part is provided after the supporting member is raised to make the opening of the shell higher than the liquid level of the shell material in the shell material tank.

According to the three-dimensional modeling method (4), the leak prevention part is provided after the support member is raised to make the opening of the shell higher than the liquid level of the shell material in the shell material tank, so that the leakage It is possible to employ means for efficiently shaping the prevention portion in a shorter time, such as means for rapidly curing a wide surface.

Further, the method for manufacturing a three-dimensional object according to the present invention is characterized in that the three-dimensional object is manufactured using any one of the three-dimensional object forming methods (1) to (4) described above.

According to the method for manufacturing a three-dimensional object, when manufacturing the three-dimensional object, the effects obtained by any of the three-dimensional object forming methods (1) to (4) are achieved, and the core part is It is possible to eliminate internal contamination of the apparatus due to material spillage and the process of refilling the core material, thereby increasing the manufacturing efficiency of the three-dimensional molded object.

1 is a schematic diagram showing a configuration example of a three-dimensional modeling apparatus used in a three-dimensional modeling method according to an embodiment of the present invention. It is a flow chart for explaining an example of the three-dimensional modeling method concerning an embodiment. FIG. 3 is a partial cross-sectional view schematically showing a state in which a shell is formed on a modeling table in a shell forming step (S1). FIG. 3 is a partial cross-sectional view schematically showing a state in which a core portion is filled with a core material in a core material filling step (S2). FIG. 3 is a partial cross-sectional view schematically showing a state in which a leak prevention portion is formed at the opening of the shell in the leak prevention portion forming step (S4). FIG. 7 is a partial cross-sectional view schematically showing a scene in which a shell in which a leakage prevention portion is formed is being removed from a modeling table in a shell removal step (S5). FIGS. 3A and 3B are diagrams for explaining a leakage prevention part forming step in a three-dimensional modeling method according to another embodiment, in which (a) shows a state when the leakage prevention part is being modeled, and (b) shows a state in which the leakage prevention part is being modeled; FIG. 3 is a partial cross-sectional view schematically showing the state after the FIG. 1 is a perspective view schematically showing an example of a three-dimensional structure formed by a core-shell method. FIG. 2 is a partial cross-sectional view schematically showing a state in which a shell formed by a core-shell method on a modeling table using a three-dimensional modeling apparatus using a liquid bath polymerization method is exposed on the surface of a liquid bath. FIG. 2 is a partial cross-sectional view schematically showing a scene in which a shell modeled using a core-shell method is being removed from a model table.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a three-dimensional modeling method and a three-dimensional molded object manufacturing method according to the present invention will be described based on the drawings. Note that the three-dimensional objects shown in the drawings, as well as the forms of their shells and core parts, are schematically drawn so that the gist of the present invention can be easily understood, and the present invention is not limited to these forms. isn't it.

FIG. 1 is a schematic diagram showing a configuration example of a three-dimensional modeling apparatus used in a three-dimensional modeling method according to an embodiment.
The three-dimensional modeling apparatus 10 mainly includes a modeling tank (shell material tank) 11, a laser optical system 12, a core material supply system 13, and a control unit 20 that controls the operations of these parts.

The three-dimensional modeling apparatus 10 is an apparatus that uses a liquid bath polymerization method to form a shell 2 of a three-dimensional object 1 that is formed using a core-shell method. The three-dimensional modeling apparatus 10 is configured as a composite material 3D printer, and a thermosetting resin is used as a core material 5 to be filled in a core part 4, which is a part surrounded by a shell 2 and has a bottom surface. A reinforced resin with a reinforcing material dispersed therein is used.
Note that FIG. 1 schematically shows a state in which the modeling of the shell 2 performed in the modeling tank 11 into which the shell material 3 has been injected and the filling of the core material 5 into the core part 4 have been completed. Further, in the figure, the direction of the arrow x is the x-axis direction, the direction of the arrow z is the z-axis direction, and the direction perpendicular to the plane of the paper is the y-axis direction.

In the modeling tank 11, for example, a photocurable resin which is a liquid phase material is stored as the shell material 3, and its liquid level is maintained and adjusted at a predetermined position by a photocurable resin adjustment system (not shown). It is possible. For the shell material 3, for example, a photocurable resin such as a known ultraviolet curing resin such as an epoxy resin or an acrylic resin can be used. Further, a modeling table 15 is provided in the modeling tank 11 . The modeling table 15 is an example of a support member that supports the three-dimensional object 1 being modeled, and can be moved and installed at any position in the z-axis direction in the figure by a drive mechanism (not shown). Note that the operation of the modeling table 15 can be controlled by the control unit 20.

A recoater 16 is disposed near the liquid surface of the modeling tank 11, and with the tip of the recoater 16 slightly submerged in the liquid surface of the shell material 3 (for example, by less than a predetermined hardening depth), the recoater 16 is placed in the horizontal direction ( In this case, it is possible to move in the x-axis direction). Recoater 16 is an example of a blade. This movement of the recoater 16 spreads the shell material 3 on the shell 2 being modeled to a uniform thickness, scrapes off the excess core material 5, and spreads the shell material 3 on the shell 2 and the core material 5. It is possible to spread the shell material 3 flatly to a predetermined depth (for example, about 0.1 mm to 0.4 mm). Note that the operation of the recoater 16 can be controlled by a control unit 20.

The laser optical system 12 includes an ultraviolet laser 12a and a scanning optical system 12b. The ultraviolet laser beam 12c is emitted from the ultraviolet laser 12a, and the emitted ultraviolet laser beam 12c can scan a predetermined range on the liquid surface of the shell material 3 (that is, the xy plane) by driving the scanning optical system 12b. There is. The ultraviolet curing resin as the shell material 3 is cured by a predetermined depth from the liquid surface by irradiation with ultraviolet laser light 12c, which is one of the active energy rays, and the shell 2 is shaped. This curing depth can be adjusted within a certain range by adjusting the output of the ultraviolet laser 12a, and is usually set to about 0.1 mm to 0.4 mm. Therefore, by lowering the molding table 15 so that the molding surface is at a position submerged by a predetermined curing depth from the liquid level of the shell material 3, and repeating the scanning of irradiating the ultraviolet laser beam 12c, the molding table 15 Shell 2 is designed to be molded on top.

Note that between the modeling table 15 and the shell 2, a support portion (also referred to as a support material) 6 for supporting the shell 2 during modeling is formed using the shell material 3. The support portion 6 is formed into a shape necessary to support the shell 2 and a removable shape, such as a plurality of thin rods or a mesh shape, by irradiating the shell material 3 with ultraviolet laser light 12c. The operation of each part of the laser optical system 12 can be controlled by a control unit 20.

The core material supply system 13 supplies the core material 5 from the core material tank 13a storing therein by pressure-feeding it through piping systems 13c and 13d in order with a pump 13b, and discharges the core material 5 from the tip of the nozzle 14. do. The nozzle 14 can be moved and fixed in each of the x, y, and z directions in the figure by a nozzle moving mechanism (not shown). For this reason, the piping system 13d has a flexible structure and material so as to follow the movement of the nozzle 14. The operation of the pump 13b, nozzle 14, etc. of the core material supply system 13 is also controlled by the control unit 20.

The core material 5 is made of a composite material in which a reinforcing material is uniformly dispersed in a thermosetting resin that is a known liquid phase material such as epoxy or acrylic, but is not limited thereto. When such a composite material is used, it is possible to cure the reinforcing material in a state where it is uniformly dispersed in the base material. In other words, it becomes possible to harden the reinforcing material without causing disruption of the dispersed state, and the strength of the three-dimensional structure can be increased. The reinforcing material may be, for example, a fibrous reinforcing material containing at least one of carbon fiber, glass fiber, and aramid fiber, or may be an inorganic material powder such as silica. The core material 5 used has a higher specific gravity than the shell material 3.

Note that the core material 5 may have a viscosity of, for example, 1000 to 5000 (mPa·s), more preferably 1000 to 2000 (mPa·s). Further, the ultraviolet curing resin that is the shell material 3 can have a viscosity of, for example, 200 to 700 (mPa·s), and the viscosity of the core material 5 is at least twice that of the shell material 3. It is preferable.

The control unit 20 includes a storage section 20a that includes one or more storage devices, and a control section 20b that includes one or more computers (arithmetic processing units), and can be configured as a computer device. .
The storage unit 20a includes additional information such as a program for causing the control unit 20b to execute the three-dimensional modeling method according to the embodiment, 3D data (three-dimensional CAD data) of the three-dimensional object to be modeled, and other setting data for modeling conditions. Various data necessary for manufacturing are stored.
The control unit 20b reads out the program, the 3D data, the setting data, etc. from the storage unit 20a, and controls each part of the laser optical system 12, each part of the core material supply system 13, and the modeling tank 11 based on the program. Appropriate control signals and drive signals are output to the provided modeling table 15, recoater 16, etc., and processing for controlling the operations of these parts is executed.

Note that a waste bucket (not shown) may be provided in the vicinity of the modeling table 15 in the modeling tank 11. By providing the waste bucket, the excess core material 5 scraped off by the recoater 16 after the core portion 4 is filled with excess can be discarded (recovered). The waste pail may be disposed so as to be movable up and down together with the modeling table 15, or may be disposed so as to be movable up and down separately from the modeling table 15.

FIG. 2 is a flowchart for explaining an example of the three-dimensional modeling method according to the embodiment. The three-dimensional modeling method according to the embodiment is a so-called core-shell three-dimensional modeling method. In the following description, an example will be described in which the shell 2, which is the outer shell layer of the three-dimensional structure 1, is formed in multiple steps. Of course, depending on the size of the three-dimensional object 1 and the shape of the core part 4, it may be possible to form the shell 2 in one go without dividing it, but basically the same procedure is repeated. There is no essential difference in the modeling method.

First, a shell forming step (S1) is performed in which the shell 2, which is the outer shell layer of the three-dimensional object 1, is formed on the modeling table 15 using the shell material 3, which is a liquid phase material.
That is, the control unit 20 controls the laser optical system 12 and the modeling table 15, scans the ultraviolet laser beam 12c on the printing area on the modeling table 15, and moves the modeling table 15 to a predetermined height (depth) in the Z direction. ) (one layer at a time), the shell 2 is molded on the molding table 15. When shaping the shell 2 one layer at a time, it is preferable to level the liquid level of the shell material 3 in the x-axis direction with the recoater 16 and then scan with the ultraviolet laser beam 12c.

In addition, in the shell modeling process (S1), the support part 6 is modeled between the modeling table 15 and the shell 2. The support part 6 is for supporting the shell 2. For example, by irradiating the shell material 3 with ultraviolet laser light 12c, a plurality of thin rods, mesh shapes, etc. necessary for supporting the shell 2 are formed. Shaped into a removable shape. Moreover, the above-mentioned one layer is set in consideration of the curing depth of the ultraviolet laser beam 12c. The curing depth may be set, for example, to about 0.1 mm to 0.4 mm.

FIG. 3 is a partial cross-sectional view schematically showing a state in which the shell 2 is formed on the forming table 15 in the shell forming step (S1). Note that FIG. 3 shows a state in which the shell 2 has been modeled for the first time, and only the surrounding area of the modeling table 15 is shown in an enlarged manner.
As shown in FIG. 3, a shell 2 is formed on a forming table 15 via a support portion 6. As shown in FIG. The shell 2 is shaped like a bottomed box having an opening 2a at the top. At this point, the uncured shell material 3 remains inside the shell 2, that is, in the core portion 4 surrounded by the shell 2 formed the first time. In addition, when the shell 2 is modeled for the second time, the core material 5 is filled in the area of the core part 4 surrounded by the shell 2 that is modeled for the first time, and the core material 5 is filled with the core material 5. The uncured shell material 3 remains in the enclosed area of the core portion 4.

Next, a core material filling step (S2) is performed in which the core portion 4, which is the portion surrounded by the shell 2, is filled with the core material 5, which is a liquid phase material.
That is, the control unit 20 controls the core material supply system 13 and operates a nozzle moving mechanism (not shown) to insert the nozzle 14 into the core part 4 through the opening 2a of the shell 2, and insert the nozzle 14 into the core part 4. Place it near the bottom of. In this state, the control unit 20 drives the pump 13b to slowly discharge the core material 5 from the tip of the nozzle 14, filling the core portion 4 with the core material 5.

FIG. 4 is a partial cross-sectional view schematically showing a state in which the core material 5 is filled into the core part 4 in the core material filling step (S2), and only the surrounding area of the modeling table 15 is shown in an enlarged manner. Note that FIG. 4 shows a state in which the core part 4 is filled with the core material 5 after the second shell 2 is modeled, and the ultraviolet curing resin that is the shell material 3 is placed on top of the filled core material 5. is listed.

In the core material filling step (S2), as the core material 5 is supplied from the nozzle 14 inserted near the bottom of the core part 4, the uncured shell material 3 remaining in the core part 4 is mixed with the two sides of the shaped shell. It overflows from the edges, and the uncured shell material 3 in the core portion 4 is gradually replaced by the core material 5 from the bottom. Thereafter, when the core portion 4 is filled with a predetermined amount of the core material 5, the filling process is completed. Note that since the specific gravity of the core material 5 is greater than the specific gravity of the shell material 3, the core material 5 settles into the uncured shell material 3 under its own weight. Therefore, the bottom part of the core part 4 can be replaced with the shell material 3 more easily. In the core material filling step (S2), after filling the core material 5, the recoater 16 levels the liquid level of the shell material 3 in the x-axis direction, scrapes off the excess core material 5, and removes the excess core material. The material 5 may be disposed of in a waste bucket (not shown).

Next, the control unit 20 determines whether or not the modeling of the shell 2 and the filling of the core material 5 are all completed (S3), and determines that the modeling of the shell 2 and the filling of the core material 5 are not completely completed. For example, the process returns to the shell forming step (S1) and executes the second and subsequent shell forming steps (S1) and the core material filling step (S2).
On the other hand, if it is determined that the shaping of the shell 2 and the filling of the core material 5 are all completed, then a leakage prevention part forming step (S4) in which a leakage prevention part is provided in the opening 2a of the shell 2 is performed.

FIG. 5 is a partial cross-sectional view schematically showing a state in which the leak prevention part 7 is formed in the opening 2a of the shell 2 in the leak prevention part forming step (S4).
In the leakage prevention part forming step (S4), the control unit 20 controls at least the laser optical system 12 to scan and irradiate the opening 2a of the shell 2 with the ultraviolet laser beam 12c, so that the opening 2a of the shell 2 is exposed to The leakage prevention part 7 is shaped by hardening the shell material 3 (see FIG. 4).

The shaped leakage prevention part 7 seals the opening 2a of the shell 2, that is, the upper surface of the core part 4, and the core material 5 of the core part 4 is trapped by the shell 2 and the leakage prevention part 7. become a state. Note that the shell material 3 (see FIG. 4) placed on the core material 5 may be completely cured as shown in FIG. 5, or at least a portion of the shell material 3, for example, the surface portion of the shell material 3 Only the entire shell 2 may be hardened, or the inner edge portion of the opening 2a of the shell 2 may be hardened.

In the leakage prevention part forming step (S4), ultraviolet laser light 12c is irradiated under conditions such that the hardening depth of the shell material 3 at the time of modeling the leakage prevention part 7 is deeper than the hardening depth of the shell material 3 at the time of modeling the shell 2. You may. By adjusting the scanning conditions of the ultraviolet laser beam 12c so that the curing depth becomes deep, it becomes possible to cure the shell material 3 with a depth of about 0.5 mm in one scan.

Further, in the leakage prevention portion forming step (S4), the leakage prevention portion 7 may be formed under the same conditions as when the shell 2 is formed. That is, the control unit 20 controls the modeling table 15 to be slightly raised from the state shown in FIG. 3 to form an uncured layer. Thereafter, the control unit 20 performs control to scan and irradiate at least the upper end surface of the core portion 4 with the ultraviolet laser beam 12c, thereby forming one layer of the leakage prevention portion 7. After that, the control unit 20 controls the modeling table 15 to be lowered by a predetermined depth (for example, a depth of 0.1 mm), and the uncured layer of the shell material 3 is placed on the previously formed leakage prevention part 7. form. Then, the control unit 20 performs control to scan and irradiate the ultraviolet laser beam 12c toward the upper surface of the leak prevention part 7 that has been modeled previously, thereby modeling the next layer of the leak prevention part 7. In this way, the process of forming the leakage prevention part 7 layer by layer may be repeated to form the leakage prevention part 7 having a predetermined thickness.

After completing the leakage prevention portion forming step (S4), a shell removing step (S5) in which the shell 2 is removed from the modeling table 15 is performed.
FIG. 6 is a partial sectional view schematically showing a scene in which the shell 2 on which the leakage prevention portion 7 is formed is being removed from the modeling table 15 in the shell removal step (S5).

In the shell removal step (S5), the control unit 20 controls the molding table 15 to raise the molding table 15 in the molding tank 11 above the liquid level of the shell material 3. Next, the operator gradually inserts a peeling tool 50 such as a spatula or scraper into the support part 6 between the modeling table 15 and the shell 2, and removes the shell 2 while breaking the support part 6.

In this step, the core material 5 filled in the core part 4 is in a liquid state, but since the leakage prevention part 7 is formed in the opening 2a of the shell 2, the shell 2 is formed using a peeling tool 50 or the like. Even if the shell 2 is tilted or vibration is applied to the shell 2 when it is removed from the stand 15, there is no risk of the core material 5 spilling out from the core part 4.
Therefore, in the shell removal step (S5), the core material 5 is not spilled onto the modeling table 15 and the modeling table 15 etc. are not contaminated, and the removal work can be performed efficiently.

Then, the shell 2 removed from the modeling table 15 is put into a heating furnace, for example, and thermal energy is applied to the core material 5 to harden the liquid core material 5 in the core part 4, thereby creating a three-dimensional shape. The entire modeling of the object 1 is completed. In addition, the leakage prevention part 7 may be left as it is as a part of the structure of the three-dimensional structure 1, or at least a part of the leakage prevention part 7 may be removed from the three-dimensional structure 1.

According to the three-dimensional modeling method according to the above embodiment, since the leakage prevention part forming step (S4) is provided between the core material filling step (S2) and the shell removing step (S5), the shell 2 It becomes possible to perform the shell removal step (S5) in a state where the leakage prevention part 7 is provided in the opening 2a (that is, the upper surface of the core material 5 filled in the core part 4). By providing the leakage prevention part 7 in the opening 2a of the shell 2 in this way, even if the shell 2 is tilted or vibration is applied to the shell 2 during the shell removal process (S5), the core can be prevented. There is no possibility that the uncured core material 5 will spill from the core part 4, and the shell 2 can be removed from the modeling table 15 without spilling the core material 5 from the core part 4.

Further, according to the three-dimensional modeling method according to the above embodiment, the leakage prevention part 7 is formed by irradiating at least a part of the shell material 3 located on the core material 5 with active energy such as ultraviolet laser light 12c to harden it. Therefore, after the core material filling step (S2) is finished, the leakage prevention part 7 can be easily and efficiently shaped.

Further, according to the three-dimensional modeling method according to the above embodiment, the hardening depth of the shell material 3 when molding the leakage prevention part 7 is deeper than the hardening depth of the shell material 3 when molding the shell 2. The leakage prevention part 7 can be efficiently shaped in a short time.

Furthermore, by manufacturing the three-dimensional object 1 using the three-dimensional modeling method according to the embodiment described above, the above-mentioned effects can be achieved when the three-dimensional object 1 is manufactured, and the core material 5 does not spill out from the core part 4. It is possible to eliminate contamination in the apparatus due to the above, and the process of replenishing the core material 5, etc., and the manufacturing efficiency of the three-dimensional molded object 1 can be improved.

In addition, in the leakage prevention part forming step (S4) in the three-dimensional modeling method according to the embodiment described above, the leakage prevention part 7 is formed by curing at least a part of the shell material 3 located on the core material 5. However, the method of forming the leakage prevention part 7 is not limited to this method.

FIG. 7 is a diagram for explaining the leakage prevention part forming step (S4a) in the three-dimensional modeling method according to another embodiment, in which (a) shows the state when the leakage prevention part is being modeled, and (b) ) is a partial cross-sectional view schematically showing the state after the leakage prevention part is formed. Note that the shell forming step (S1), the core material filling step (S2), and the shell removing step (S5) are substantially the same as the method described using FIG. 2, so their description will be omitted here.

The three-dimensional modeling apparatus used in the three-dimensional modeling method according to another embodiment is different from the three-dimensional modeling apparatus 10 shown in FIG. The other configurations are the same.

In the leakage prevention part forming step (S4a) according to another embodiment, after all the modeling of the shell 2 is completed, the control unit 20 controls the modeling table 15 so that the opening 2a of the shell 2 The modeling table 15 is raised to a position higher than the liquid level of the shell material 3. In this state, the shell material 3 is placed on the core material 5.

Next, the control unit 20 controls the ultraviolet curing lamp 17 provided above the modeling tank 11 to irradiate the shell material 3 placed on the core material 5 (FIG. 7(a)). The shell material 3 placed on the material 5 is hardened. Through this lamp irradiation treatment, a leakage prevention part 7 is formed on the core material 5 (FIG. 7(b)).

Note that the irradiation intensity of the ultraviolet curing lamp 17 and the height position of the modeling table 15 mean that the shell material 3 in the modeling tank 11 in which the modeling table 15 is submerged is not cured, but the core portion surrounded by the shell 2 is The relationship between the strength at which only the shell material 3 placed on the core material 5 of No. 4 is hardened and the height position of the modeling table 15 is adjusted.

According to the three-dimensional modeling method according to the above-described another embodiment, the leakage prevention part forming step (S4a) involves raising the modeling table 15 and adjusting the opening 2a of the shell 2 to the liquid level of the shell material 3 in the modeling tank 11. After increasing the height, the entire surface of the shell material 3 placed on the core material 5 is irradiated with an ultraviolet curing lamp 17 at once to form the leakage prevention portion 7. Therefore, the leakage prevention part 7 can be shaped more efficiently in a shorter time.

The present invention is not limited to the above-described embodiments, and various modifications can be made to the above-described leakage prevention part forming process, and these are also included within the scope of the present invention. Needless to say. Furthermore, in the above embodiment, a case has been described in which the shell material 3 used to form the shell 2 is a liquid phase material, but the shell 2 is formed using a method of curing a liquid phase material (liquid phase polymerization method). The invention is not limited to this, and other additive manufacturing methods described in the background art section above may be applied.
The present invention is widely applicable in the field of additive manufacturing technology such as 3D printers, and by applying the present invention to such fields, for example, parts used in various industrial equipment such as automobiles, aircraft, robots, nursing care products, etc. It becomes possible not only to prototype but also to mass-produce parts and products that require light weight and high strength, such as sports equipment.

1,100 Three-dimensional object 2 Shell 2a Opening 3 Shell material 4 Core portion 5 Core material 6 Support portion 7 Leakage prevention portion 10 Three-dimensional modeling device 11 Modeling tank (shell material tank)
12 Laser optical system 12a Ultraviolet laser 12b Scanning optical system 12c Ultraviolet laser beam 13 Core material supply system 13a Core material tank 13b Pumps 13c, 13d Piping system 14 Nozzle 15 Modeling table (supporting member)
16 Recoater 17 UV curing lamp 20 Control unit 20a Storage section 20b Control section

Claims (5)

a shell forming step of forming a shell, which is an outer shell layer of the three-dimensional model, on a support member using a shell material;
a core material filling step of filling a core material, which is a liquid phase material, into a core portion that is a portion surrounded by the shell;
a shell removal step of removing the shell from the support member;
A three-dimensional modeling method for forming a three-dimensional object including the core material,
A three-dimensional modeling method, comprising a step of forming a leak prevention portion in an opening of the shell between the core material filling step and the shell removal step. 2. The three-dimensional modeling method according to claim 1, wherein the leakage prevention part is formed by curing at least a portion of the shell material located on the core material. 3. The three-dimensional modeling method according to claim 2, wherein the hardening depth of the shell material during modeling of the leakage prevention part is deeper than the hardening depth of the shell material during modeling of the shell. The shell is formed in a shell material tank into which the shell material is injected,
In the leakage prevention part forming step, the leakage prevention part is provided after the support member is raised to make the opening of the shell higher than the liquid level of the shell material in the shell material tank. The three-dimensional modeling method according to any one of items 1 to 3. A method for manufacturing a three-dimensional object, the method comprising manufacturing the three-dimensional object using the three-dimensional object forming method according to any one of claims 1 to 4.

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